Edit in JSFiddle

function setupSomeGlobals() {
    // Local variable that ends up within closure
    var num = 666;
    // Store some references to functions as global variables
    gAlertNumber = function() { console.log(num); }
    gIncreaseNumber = function() { num++; }
    gSetNumber = function(x) { num = x; }
}

setupSomeGlobals();
gIncreaseNumber();
gAlertNumber();
gSetNumber(5);
gAlertNumber();

var oldAlert = gAlertNumber;

setupSomeGlobals();
gAlertNumber(); 

oldAlert();